[PATCH v2 REPOST 05/12] tools/libxenctrl: use new xenforeignmemory API to seed grant table

[Paul Durrant <paul.durrant@citrix.com>]

A previous patch added support for priv-mapping guest resources directly
(rather than having to foreign-map, which requires P2M modification for
HVM guests).

This patch makes use of the new API to seed the guest grant table unless
the underlying infrastructure (i.e. privcmd) doesn't support it, in which
case the old scheme is used.

NOTE: The call to xc_dom_gnttab_hvm_seed() in hvm_build_set_params() was
      actually unnecessary, as the grant table has already been seeded
      by a prior call to xc_dom_gnttab_init() made by libxl__build_dom().

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxc/include/xc_dom.h        |   8 +--
 tools/libxc/xc_dom_boot.c           | 102 ++++++++++++++++++++++++++++--------
 tools/libxc/xc_sr_restore_x86_hvm.c |  10 ++--
 tools/libxc/xc_sr_restore_x86_pv.c  |   2 +-
 tools/libxl/libxl_dom.c             |   1 -
 tools/python/xen/lowlevel/xc/xc.c   |   6 +--
 6 files changed, 92 insertions(+), 37 deletions(-)

diff --git a/tools/libxc/include/xc_dom.h b/tools/libxc/include/xc_dom.h
index ce47058c41..d6ca0a8680 100644
--- a/tools/libxc/include/xc_dom.h
+++ b/tools/libxc/include/xc_dom.h
@@ -323,12 +323,8 @@ void *xc_dom_boot_domU_map(struct xc_dom_image *dom, xen_pfn_t pfn,
 int xc_dom_boot_image(struct xc_dom_image *dom);
 int xc_dom_compat_check(struct xc_dom_image *dom);
 int xc_dom_gnttab_init(struct xc_dom_image *dom);
-int xc_dom_gnttab_hvm_seed(xc_interface *xch, domid_t domid,
-                           xen_pfn_t console_gmfn,
-                           xen_pfn_t xenstore_gmfn,
-                           domid_t console_domid,
-                           domid_t xenstore_domid);
-int xc_dom_gnttab_seed(xc_interface *xch, domid_t domid,
+int xc_dom_gnttab_seed(xc_interface *xch, domid_t guest_domid,
+                       bool is_hvm,
                        xen_pfn_t console_gmfn,
                        xen_pfn_t xenstore_gmfn,
                        domid_t console_domid,
diff --git a/tools/libxc/xc_dom_boot.c b/tools/libxc/xc_dom_boot.c
index c3b44dd399..fc3174ad7e 100644
--- a/tools/libxc/xc_dom_boot.c
+++ b/tools/libxc/xc_dom_boot.c
@@ -280,11 +280,11 @@ static xen_pfn_t xc_dom_gnttab_setup(xc_interface *xch, domid_t domid)
     return gmfn;
 }
 
-int xc_dom_gnttab_seed(xc_interface *xch, domid_t domid,
-                       xen_pfn_t console_gmfn,
-                       xen_pfn_t xenstore_gmfn,
-                       domid_t console_domid,
-                       domid_t xenstore_domid)
+static int compat_gnttab_seed(xc_interface *xch, domid_t domid,
+                              xen_pfn_t console_gmfn,
+                              xen_pfn_t xenstore_gmfn,
+                              domid_t console_domid,
+                              domid_t xenstore_domid)
 {
 
     xen_pfn_t gnttab_gmfn;
@@ -337,11 +337,11 @@ int xc_dom_gnttab_seed(xc_interface *xch, domid_t domid,
     return 0;
 }
 
-int xc_dom_gnttab_hvm_seed(xc_interface *xch, domid_t domid,
-                           xen_pfn_t console_gpfn,
-                           xen_pfn_t xenstore_gpfn,
-                           domid_t console_domid,
-                           domid_t xenstore_domid)
+static int compat_gnttab_hvm_seed(xc_interface *xch, domid_t domid,
+                                  xen_pfn_t console_gpfn,
+                                  xen_pfn_t xenstore_gpfn,
+                                  domid_t console_domid,
+                                  domid_t xenstore_domid)
 {
     int rc;
     xen_pfn_t scratch_gpfn;
@@ -380,7 +380,7 @@ int xc_dom_gnttab_hvm_seed(xc_interface *xch, domid_t domid,
         return -1;
     }
 
-    rc = xc_dom_gnttab_seed(xch, domid,
+    rc = compat_gnttab_seed(xch, domid,
                             console_gpfn, xenstore_gpfn,
                             console_domid, xenstore_domid);
     if (rc != 0)
@@ -405,18 +405,78 @@ int xc_dom_gnttab_hvm_seed(xc_interface *xch, domid_t domid,
     return 0;
 }
 
-int xc_dom_gnttab_init(struct xc_dom_image *dom)
+int xc_dom_gnttab_seed(xc_interface *xch, domid_t guest_domid,
+                       bool is_hvm, xen_pfn_t console_gmfn,
+                       xen_pfn_t xenstore_gmfn, domid_t console_domid,
+                       domid_t xenstore_domid)
 {
-    if ( xc_dom_translated(dom) ) {
-        return xc_dom_gnttab_hvm_seed(dom->xch, dom->guest_domid,
-                                      dom->console_pfn, dom->xenstore_pfn,
-                                      dom->console_domid, dom->xenstore_domid);
-    } else {
-        return xc_dom_gnttab_seed(dom->xch, dom->guest_domid,
-                                  xc_dom_p2m(dom, dom->console_pfn),
-                                  xc_dom_p2m(dom, dom->xenstore_pfn),
-                                  dom->console_domid, dom->xenstore_domid);
+    xenforeignmemory_handle* fmem = xch->fmem;
+    xenforeignmemory_resource_handle *fres;
+    void *addr = NULL;
+    grant_entry_v1_t *gnttab;
+
+    fres = xenforeignmemory_map_resource(fmem, guest_domid,
+                                         XENMEM_resource_grant_table,
+                                         0, 0, 1,
+                                         &addr, PROT_READ | PROT_WRITE, 0);
+    if ( !fres )
+    {
+        if ( errno == EOPNOTSUPP )
+            return is_hvm ?
+                compat_gnttab_hvm_seed(xch, guest_domid,
+                                       console_gmfn, xenstore_gmfn,
+                                       console_domid, xenstore_domid) :
+                compat_gnttab_seed(xch, guest_domid,
+                                   console_gmfn, xenstore_gmfn,
+                                   console_domid, xenstore_domid);
+
+        xc_dom_panic(xch, XC_INTERNAL_ERROR,
+                     "%s: failed to acquire grant table "
+                     "[errno=%d]\n",
+                     __FUNCTION__, errno);
+        return -1;
     }
+
+    gnttab = addr;
+
+    if ( guest_domid != console_domid  && console_gmfn != -1)
+    {
+        xc_dom_printf(xch, "%s: setting console pfn=0x%"PRI_xen_pfn,
+                      __FUNCTION__, console_gmfn);
+
+        gnttab[GNTTAB_RESERVED_CONSOLE].flags = GTF_permit_access;
+        gnttab[GNTTAB_RESERVED_CONSOLE].domid = console_domid;
+        gnttab[GNTTAB_RESERVED_CONSOLE].frame = console_gmfn;
+    }
+
+    if ( guest_domid != xenstore_domid && xenstore_gmfn != -1)
+    {
+        xc_dom_printf(xch, "%s: setting xenstore pfn=0x%"PRI_xen_pfn,
+                      __FUNCTION__, xenstore_gmfn);
+
+        gnttab[GNTTAB_RESERVED_XENSTORE].flags = GTF_permit_access;
+        gnttab[GNTTAB_RESERVED_XENSTORE].domid = xenstore_domid;
+        gnttab[GNTTAB_RESERVED_XENSTORE].frame = xenstore_gmfn;
+    }
+
+    xenforeignmemory_unmap_resource(fmem, fres);
+
+    return 0;
+}
+
+int xc_dom_gnttab_init(struct xc_dom_image *dom)
+{
+    xc_interface *xch = dom->xch;
+    domid_t guest_domid = dom->guest_domid;
+    bool is_hvm = xc_dom_translated(dom);
+    xen_pfn_t console_gmfn = xc_dom_p2m(dom, dom->console_pfn);
+    xen_pfn_t xenstore_gmfn = xc_dom_p2m(dom, dom->xenstore_pfn);
+    domid_t console_domid = dom->console_domid;
+    domid_t xenstore_domid = dom->xenstore_domid;
+
+    return xc_dom_gnttab_seed(xch, guest_domid, is_hvm,
+                              console_gmfn, xenstore_gmfn,
+                              console_domid, xenstore_domid);
 }
 
 /*
diff --git a/tools/libxc/xc_sr_restore_x86_hvm.c b/tools/libxc/xc_sr_restore_x86_hvm.c
index 1dca85354a..a5c661da8f 100644
--- a/tools/libxc/xc_sr_restore_x86_hvm.c
+++ b/tools/libxc/xc_sr_restore_x86_hvm.c
@@ -207,11 +207,11 @@ static int x86_hvm_stream_complete(struct xc_sr_context *ctx)
         return rc;
     }
 
-    rc = xc_dom_gnttab_hvm_seed(xch, ctx->domid,
-                                ctx->restore.console_gfn,
-                                ctx->restore.xenstore_gfn,
-                                ctx->restore.console_domid,
-                                ctx->restore.xenstore_domid);
+    rc = xc_dom_gnttab_seed(xch, ctx->domid, true,
+                            ctx->restore.console_gfn,
+                            ctx->restore.xenstore_gfn,
+                            ctx->restore.console_domid,
+                            ctx->restore.xenstore_domid);
     if ( rc )
     {
         PERROR("Failed to seed grant table");
diff --git a/tools/libxc/xc_sr_restore_x86_pv.c b/tools/libxc/xc_sr_restore_x86_pv.c
index 50e25c162c..10635d436b 100644
--- a/tools/libxc/xc_sr_restore_x86_pv.c
+++ b/tools/libxc/xc_sr_restore_x86_pv.c
@@ -1104,7 +1104,7 @@ static int x86_pv_stream_complete(struct xc_sr_context *ctx)
     if ( rc )
         return rc;
 
-    rc = xc_dom_gnttab_seed(xch, ctx->domid,
+    rc = xc_dom_gnttab_seed(xch, ctx->domid, false,
                             ctx->restore.console_gfn,
                             ctx->restore.xenstore_gfn,
                             ctx->restore.console_domid,
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index f54fd49a73..0d3e462c12 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -851,7 +851,6 @@ static int hvm_build_set_params(xc_interface *handle, uint32_t domid,
     *store_mfn = str_mfn;
     *console_mfn = cons_mfn;
 
-    xc_dom_gnttab_hvm_seed(handle, domid, *console_mfn, *store_mfn, console_domid, store_domid);
     return 0;
 }
 
diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c
index aa9f8e4d9e..583ab52a6f 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -800,9 +800,9 @@ static PyObject *pyxc_gnttab_hvm_seed(XcObject *self,
 				      &console_domid, &xenstore_domid) )
         return NULL;
 
-    if ( xc_dom_gnttab_hvm_seed(self->xc_handle, dom,
-				console_gmfn, xenstore_gmfn,
-				console_domid, xenstore_domid) != 0 )
+    if ( xc_dom_gnttab_seed(self->xc_handle, dom, true,
+                            console_gmfn, xenstore_gmfn,
+                            console_domid, xenstore_domid) != 0 )
         return pyxc_error_to_exception(self->xc_handle);
 
     return Py_None;
-- 
2.11.0


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